docs: 更新README，添加v2.2.0优化记录

Author: badhope

README.md

@@ -91,10 +91,19 @@
 
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-## 🆕 Latest Update (v2.1.0)
+## 🆕 Latest Update (v2.2.0)
 
 ### Major Improvements
 
+#### 🚀 Performance & Quality Optimization
+- ✅ **Code Quality**: Removed 25+ unused imports and variables
+- ✅ **Performance**: Implemented lazy loading for all routes
+- ✅ **SEO**: Added Open Graph, Twitter Card, and structured data
+- ✅ **Accessibility**: Enhanced ARIA labels and keyboard navigation
+- ✅ **Mobile**: Optimized responsive design for all devices
+- ✅ **Type Safety**: Zero TypeScript errors with strict mode
+- ✅ **Build**: Optimized chunk splitting for faster loading
+
 #### 📚 Enhanced Question Banks
 - **MBTI Assessment**: Expanded to **40 questions** with optimized options
 - **Big Five (OCEAN)**: Comprehensive **20-question** personality profile